The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
With many heavy duty trucks having heavy duty transmissions, it is commonplace to have power take off components associated with the driveline. Such components generally comprehend a selectively engageable clutch, a drive gear, an idler gear and a driven gear that, when the clutch is engaged, transfer torque from the driveline axis to an axis offset from and parallel to the driveline axis and thence to a shaft or other torque transfer component.
Typically, such clutches have hydraulic operators. Typically, as well, it is accepted power take off design practice to include a two position pressure switch associated with the hydraulic fluid pressure provided to the hydraulic clutch actuator to provide an on/off or go/no go signal to a PTO controller or other electronic control module (ECM) indicating or confirming that pressure has been applied to the clutch. While such pressure switch is set to change state at a pressure indicating assured clutch engagement, wear of such components and other variables such as fluid temperature and age can and generally will change the operating point of the clutch or switch over time. From the standpoint of accurate and repeatable information regarding the state of the power take off, this inaccuracy is undesirable.